Mirra Andreeva is still waiting for the puppy her mom promised her

Mirra Andreeva's trophy case has grown exponentially in recent months, and as she gets ready to face world No. 2 Iga Swiatek in the semifinals of the BNP Paribas Open on Friday, the teenager owns the second-longest active winning streak on the WTA tour (behind only Australian Open champion Madison Keys).

But one coveted prize is still missing from the 17-year-old's house. It walks on four legs, and it barks.

Andreeva was all set to become a dog owner last fall, the result of a promise her mom begrudgingly made with her if she could break into the WTA's Top 20. The youngster was quick to remind her, and anyone who'd listen, of the bet after she secured the milestone by reaching the quarterfinals of the China Open in October.

"I think I will not buy a dog right away," she said then. "I want to buy a dog when I am super confident that I will be able to give everything I can to the dog, because it's like a little child. Now, it's a bit complicated. I need to get more mature so I can take care of my dog."

Six months later, there is still no four-legged friend to be found—though Andreeva has some ideas.

"I'm thinking to get an ultra mini labradoodle," she confessed after beating Elina Svitolina in the quarterfinals of Indian Wells on Thursday. "It's going to be a Labrador mixed with poodle, and it's ultra mini, so going to be even smaller than a mini version.

"It's going to take time until the dog that I want will be born. We wait for now."

The teenager has made no secret of her desire for a puppy—she never had a pet in her childhood—and that youth exuberance sometimes resulted in her obsessing over her progress in pursuit of earning her furry friend. But it's a habit she's since broken, thanks in part to her recent work with a sports psychologist, who she says has helped hone her focus before matches.

Read more: Mirra Andreeva: Sports psychologist helps me channel anger

"I was always checking live rankings, because before, I was playing for a dog," she said, "so after every match I play, I would check the live rankings to see if I did it.

"But now it's not that I don't care, but I try to not focus on that, and I try to focus on the match that I have to play. I like this. I would say it's pretty easy, because I don't think about the rankings or the points I have to defend if I have to, so I just don't really follow the rankings or anything, like this is a bit easier for me."

Wise beyond her years in her on-court efforts in recent months, Andreeva is also showing that maturity as it pertains to future dog ownership. There are some lingering logistics to work out, after all.

"I'm thinking to get a girl, because the girls are basically they're a bit smaller in the size, so it's gonna be easier to travel with a girl," she said.

"At first I wanted to get a boy, so I came up with a couple of names for a boy, but then we decided to get a girl," she added. "There are not many options, and I'm not even sure that the options I have are going to be the actual name. So I cannot really name any. I will have to think about it!"